In the back of my mind were tales of emulsion separating from the base, but I think those were tales of RC. I was printing on both Kentmere fineprint VC fiber and Foma 111 graded fiber.

Depends on the paper...

Option A:

Kentmere bromides and fine art papers did have specific admonitions against washing for more than a hour, unless that's changed. The emulsion would separate from the paper if "over–washed". Washing adequately, without damage could be problematic. Sometimes less than a half hour would result in damage to some discontinued warm tone fine art papers. It happened to me and was well known at Kentmere.

I've washed Oriental and Ilford papers for as long as 6 hours (accidentally), without issue.

Option B:

May be your only option unless you know a paper can withstand many hours of backstroking. I would suggest making some attempt at not allowing the paper to dry fully, perhaps keeping it in a high humidity environment until you can wash completely.

Option C:

Arrange your workflow to include proper washing times in your lab time.

I guess the good news is that I haven't seen anyone with a scary reason against drying and washing later, so if you have one please post! I wouldn't want a sub par print going out into the wild with my signature attached.

Chris

Well, here is one scary reason against letting it dry. Think of laundry. Suppose you spill something on your white shirt, and don't have the time to wash it immediately. What's the best way to avoid a permanent stain? Should you dump the shirt in a bucket of water and let it soak until you have the time to do the laundry, or should you let the stain dry and wash it later? If you don't know the answer, talk to someone who does laundry in your house. Washing photo paper is not terribly different from washing a shirt in a sense that you are trying to eliminate permanent stains.

I would do/have done the soak method.
I've never had a problem with any of the papers I've used, though 12 hours is maybe pushing things some.
For papers that have optical brightners, extended wet times could degrade the brightner, in theory at least. I've not tried any tests.

I have done option A to fiber prints many times. Not the best thing of course, but better than option B in my opinion. I feel that drying the print with residual fixer could create a wash out problem. Also, option A is not for RC paper at all. Someone came into the lab where i worked once, with about 50 RC 5 x 7 prints that had frilled on the edges. At first I was at a loss to explain it, and then I asked her, had they been in the water long? She said over night. I said BINGO.

Put the damp print into something like Tupperware or a tube that will keep it damp, take it home, and then wash in a sink or a tray in your bathtub.

Matt

“Photography is a complex and fluid medium, and its many factors are not applied in simple sequence. Rather, the process may be likened to the art of the juggler in keeping many balls in the air at one time!”

Ansel Adams, from the introduction to The Negative - The New Ansel Adams Photography Series / Book 2

I usually leave my FB prints (for 24 hours) in the washer and fully wash them during the next day's printing session. If I wouldn't do that, my printing sessions would last 5 hours and lead me to 4AM. As it is, I stop printing at 2AM and go to sleep.

All my prints have held very well. Actually, I'm sure that leaving them soaking for 24 hours washes them even better but I can't test this.

...you could always do a small test strip next time you're in the darkroom on both theories? I don't think it would be terribly time sensitive.

For the record, when I first read your post, I was siding with option B only because if you leave it in the wash too long and the emulsion lifts or something like that the print is ruined. Like most photo products, "stains" can be rinsed off in a second or third wash. I've had to do a quick wash on some prints for 10 minutes or so and clean up quickly and came back and washed them again later with no problems. These weren't exhibition prints, so I wasn't too concerned and they're still kicking after a year or so with no problems. I guess it depends on what your method of washing is and if the water is running or stale, temperature, etc. I always just leave enough time to wash thoroughly, so I've never dealt with this first hand. It seems a lot of the information your getting is speculation and not based on any scientific tests (mine included)...so if this is a constant situation for you, test both theories.

I found myself in the situation that I had to leave the darkroom before I had fully washed some prints. I could only make it back in about 12 hours.

Option A). Leave prints soaking in the washer (vertical slot washer)
Option B). After a brief soak, pull prints and put them on the drying rack (yes, I'll clean those screens!) and then do a full wash about 12 hours later.

So which do you choose and why? Not sure I want to admit which I chose quite yet

I would do/have done the soak method.
I've never had a problem with any of the papers I've used, though 12 hours is maybe pushing things some.
For papers that have optical brightners, extended wet times could degrade the brightner, in theory at least. I've not tried any tests.